Former UFC heavyweight champion Brock Lesnar returned to his roots on Monday night, appearing on WWE's "Monday Night Raw." With a glare and then an F-5 of John Cena, he jumped back into the world of professional wrestling after a four-year career in MMA. Warning: WWE fans chants some NSFW language in this video. Lesnar hasn't been in WWE since 2004 . He started fighting in 2007, and was given a title shot in the UFC in just his fourth fight. After taking the title from Randy Couture, he beat